From 3835ae3876f071958a7e059110b2b58e20629162 Mon Sep 17 00:00:00 2001
From: KtorZ <matthias.benkort@gmail.com>
Date: Mon, 16 Dec 2019 19:36:02 +0100
Subject: [PATCH] actually create one MVar per DB context ...

---
 lib/core/src/Cardano/Wallet/DB/Sqlite.hs | 32 +++++++++++++-----------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/lib/core/src/Cardano/Wallet/DB/Sqlite.hs b/lib/core/src/Cardano/Wallet/DB/Sqlite.hs
index 6fc72584a8c..e33efb9c3d7 100644
--- a/lib/core/src/Cardano/Wallet/DB/Sqlite.hs
+++ b/lib/core/src/Cardano/Wallet/DB/Sqlite.hs
@@ -220,7 +220,6 @@ newDBFactory
        -- ^ Path to database directory, or Nothing for in-memory database
     -> IO (DBFactory IO s k)
 newDBFactory cfg tr mDatabaseDir = do
-    mvar <- newEmptyMVar
     case mDatabaseDir of
         Nothing -> pure DBFactory
             { withDatabase = \_ action ->
@@ -228,20 +227,23 @@ newDBFactory cfg tr mDatabaseDir = do
             , removeDatabase = \_ ->
                 pure ()
             }
-        Just databaseDir -> pure DBFactory
-            { withDatabase = \wid action ->
-                withDBLayer cfg tracerDB (Just $ databaseFile wid) $ \(ctx,db) -> do
-                    putMVar mvar ctx
-                    action db
-            , removeDatabase = \wid -> do
-                let files =
-                        [ databaseFile wid
-                        , databaseFile wid <> "-wal"
-                        , databaseFile wid <> "-shm"
-                        ]
-                readMVar mvar >>= destroyDBLayer
-                mapM_ removePathForcibly files
-            }
+        Just databaseDir -> do
+            mvar <- newEmptyMVar
+            pure DBFactory
+                { withDatabase = \wid action ->
+                    withDBLayer cfg tracerDB (Just $ databaseFile wid)
+                        $ \(ctx,db) -> do
+                            putMVar mvar ctx
+                            action db
+                , removeDatabase = \wid -> do
+                    let files =
+                            [ databaseFile wid
+                            , databaseFile wid <> "-wal"
+                            , databaseFile wid <> "-shm"
+                            ]
+                    readMVar mvar >>= destroyDBLayer
+                    mapM_ removePathForcibly files
+                }
           where
             databaseFilePrefix = keyTypeDescriptor $ Proxy @k
             databaseFile wid =